The purpose of this article is to evaluate and critique the policy of Treasury Single Account (TSA) adopted by the Nigerian government as an essential tool for enhancing transparency and accountability in public sector financial. Theoretically, it is expected that TSA would bring about mutual benefit, halt economic injustice and engender financial discipline, transparency, accountability, a new economic and political order in Nigeria. However, in the public sector management and political economy of Nigeria, its impact has been a mixed bag of the good, the bad and the ugly. Within the framework of New Public Management approach, the paper explores the gamut of issues surrounding the implementation of TSA and concludes that, for an administration that has social contract with Nigerians in terms of service delivery; it has the obligation to aggregating states’ resources to provide social services, amenities and infrastructural development to the people. Any step taking to ensure accountability and transparency by revenue generating agencies of government should be seen as a step in the right direction. However, while change is desirable, we feel there is need to exercise caution on account of the peculiar nature and character of the Nigerian state and society. Given the catalogue of challenges facing the operations TSA, it recommends among others, that the adoption of TSA in the country’s public sector should progress slowly and wisely. Institutions and institutional rules should be strengthened, be accountable and made autonomous of cabals and individual who might want to manipulate the system for group or personal interests.